Various types of duplicating key machines are known in the prior art. With the most common type of duplicating machines, both the key blank and the key to be duplicated are rigidly secured to the same shaft which rotates about its longitudinal axis to move the blank key against the cutting wheel during the cutting operation. Moreover, in the prior art designs, the key blank and the key to be duplicated are clamped to separate clamping units, each operated by a different clamp mechanism and tighten by separate handles so that each key is clamped by a different compressive force. The design of these prior art machines results in machines which are quite expensive to produce and maintain. Also, because of the inefficient and unreliable machine performance of the prior art designs, a high percentage of unusable keys are produced.